Motor assembly and cleaner including the same

Abstract

The present disclosure relates to a motor assembly improving a coupling structure of a rotor shaft and an impeller, and a cleaner including the same. The motor assembly includes a stator, a rotor including a rotor shaft including a metallic material and configured to be rotatable by electromagnetic interaction with the stator, a hub including a plastic material and including a hollow portion configured to allow the rotor shaft to pass therethrough, and a shaft coupling member positioned between the hollow portion and the rotor shaft and including a plastic material different from a plastic material forming the hub.

1 . A motor assembly comprising:
 a stator;   a rotor comprising a rotor shaft including a metallic material and configured to be rotatable by electromagnetic interaction with the stator;   a hub including a plastic material and comprising a hollow portion configured to allow the rotor shaft to pass therethrough; and   a shaft coupling member positioned between the hollow portion and the rotor shaft and including a plastic material different from a plastic material forming the hub.   
     
     
         2 . The motor assembly according to  claim 1 , wherein
 the plastic material forming the shaft coupling member has a higher elongation at break than the plastic material forming the hub.   
     
     
         3 . The motor assembly according to  claim 1 , wherein
 the plastic material forming the shaft coupling member has a higher static friction coefficient with the metallic material than the plastic material forming the hub.   
     
     
         4 . The motor assembly according to  claim 1 , wherein
 the plastic material forming the shaft coupling member comprises a ductile material having a lower tensile strength than the plastic material forming the hub.   
     
     
         5 . The motor assembly according to  claim 1 , wherein
 the shaft coupling member comprises:   a body portion accommodated in the hollow portion; and   a head portion extending in a radial direction of the rotor shaft from an upper side of the body portion.   
     
     
         6 . The motor assembly according to  claim 5 , wherein
 a diameter of the head portion is larger than a diameter of the hollow portion to prevent the hub from being separated from the rotor shaft.   
     
     
         7 . The motor assembly according to  claim 1 , wherein
 the shaft coupling member comprises a shaft insertion hole into which the rotor shaft is inserted, and   a diameter of the shaft insertion hole is smaller than a diameter of the rotor shaft such that the rotor shaft is press-fitted into the shaft insertion hole.   
     
     
         8 . The motor assembly according to  claim 7 , wherein
 the shaft coupling member comprises a shaft coupling surface in contact with the rotor shaft press-fitted into the shaft insertion hole, and   the shaft coupling surface includes a plastic material different from the plastic material forming the hub.   
     
     
         9 . The motor assembly according to  claim 1 , wherein
 the shaft coupling member is coupled to the hollow portion in a forced fitting manner.   
     
     
         10 . The motor assembly according to  claim 1 , wherein
 the shaft coupling member is insert injection molded integrally with the hollow portion.   
     
     
         11 . The motor assembly according to  claim 1 , wherein
 the shaft coupling member is double injection molded with the hollow portion.   
     
     
         12 . The motor assembly according to  claim 5 , wherein
 the shaft coupling member further comprises a first coupling portion provided in the body portion to prevent revolving of the body portion inserted into the hollow portion.   
     
     
         13 . The motor assembly according to  claim 12 , wherein
 the hollow portion includes a second coupling portion configured to be coupled to the first coupling portion in a locking manner.   
     
     
         14 . The motor assembly according to  claim 13 , wherein
 the first coupling portion comprises a protrusion protruding in the radial direction of the rotor shaft from the body portion, and   the second coupling portion comprises a groove to allow the first coupling portion to be inserted into the second coupling portion.   
     
     
         15 . A cleaner comprising:
 a cleaner body;   a suction head configured to suck foreign substances on a surface to be cleaned into the cleaner body; and   a motor assembly disposed inside the cleaner body,   wherein the motor assembly comprises:   a motor comprising a rotor shaft and rotatably configured; and   an impeller coupled to the rotor shaft to be rotatable together with the motor, and   wherein the impeller comprises:   a hub constituted of a high strength plastic material to prevent damage due to high speed rotation of the impeller; and   a shaft coupling member coupled to a hollow portion formed in the hub and including a plastic material different from a plastic material forming the hub.